1. Field of the Invention
The present invention relates to a device for pressing out and dispensing dosed quantities of flowable multi-component compounds.
2. Description of Related Art
Multi-component compounds are increasingly used for a great number of applications industry and trade, for gluing, filling, sealing and the like. In order to prevent untimely reaction between the components, it is necessary that the different components be stored in spaces separated one from the other.
A dispensing device for flowable compounds, where a pressure is exerted on the flexible bags for the different components by application of a blowing agent, has been known from German Patent Publication 37 05 741 A1. The blowing agent is supplied into the bags, arranged in the separate containers, via respective metering devices. The metering devices consist, preferably, of volumetric pumps that are driven by electric motors. The flowable compounds are supplied to a mixing device through enlongated lines arranged in a cover element. Even if the bags are completely emptied, a considerable residual quantity remains in those lines. In addition, a device of that kind exhibits a complex structure, which requires pressure lines, relief valves and the like in addition to a tank for the blowing agent. In order to prevent the blowing agent form escaping unintentionally, sealing elements must be provided on the housing. The relief valves of the described device are intended to provide precise dosing; they permit the blowing agent to escape. A device of that kind, therefore, is not unproblematic under aspects of environmental compatibility.
European Patent No. 0 313 519 B1 describes a device for dosing and mixing at least two reaction components, where on the one hand a mixing device is guided for axial displacement by means of a spindle drive via a transmission, while on the other hand two plunger-like inserts for pressing out the cartridges are guided for axial displacement by two additional spindle drives. The two reaction components are supplied to a mixing device via lines that are integrated into the housing. Although it is an advantage of this device that pressing out the cartridges and actuating the mixing device are possible simultaneously and with only one drive spindle, it is a problem that for displacing the two plunger inserts by means of the central spindle drive a transmission and additional spindle drives are required. This leads to a complex structure of the device, which is also prone to failure, and which in addition, due to its many components, has a high weight, which is undesirable for manual operation.
In addition, these spindle drives cannot fully ensure that both cartridges are completely emptied. But even if both cartridges are completely emptied, a residual quantity of the reaction components will remain in the lines in the housing, that lead to the mixing device, and these residual quantities will cure in the course of time. Consequently, a housing of that type can only be used a single time.
German Patent Publications 196 18 693 A1 and 296 03 416 U1 disclose cartridges for component compounds filled into film bags, with storage cylinders arranged in parallel one beside the other and connected via a common inner wall, which have a headpiece or cover element attached to their front end. In the cover element, there are arranged separate channels, which extend in axial direction and are separated by a separating wall and which open into a mixing device. The devices of this type in fact efficiently prevent the two components from being mixed untimely. Mixing of multi-component compounds, especially if they are viscous, is however possible only with difficulty, because of the static mixing device. In addition, the feeding channels to the mixing device are relatively long with these devices as well, so that after the two bags have been emptied completely, there will also remain a considerable residual quantity in the cover element.